Calculus Book

Can anyone recommend an introductory Calculus book for a Grade 11 student? I know this may sound dumb, but could anyone also fill me in on how much Calculus is acutaly used in subjects like Physics? I get the impression it's used a ton...

Calculus and physics are inseparable. You can't understand physics truly without calculus, in my opinion. I've only used two different books but I liked Leithold's The Calculus. I picked up the 2nd edition a few years ago when I was a freshmeat in HS for 5 bucks and found it easy to self-study out of. I think it's up to the 7th or 8th edition now though. I'd recommend the book though over the garbage one the University I go to now has.

a classic of rigor and applications, thorough - going for serious students of science: Differential and Integral Calculus, by Richard Courant.

books for future mathematicians: Calculus, by Michael Spivak, or the book by Tom Apostol.

Suggestion: Go to a library that has several of the recommended books and look them over to see which ones you like. And look at some we have not mentioned, i.e. find your own way.

try to find one that has some proofs in it so you begin to learn to reason. My recent honors calculus classes in college are totally bereft of any experience of theory in calculus. High school courses in calculus are notoruious for omitting all the ideas and focusing only on computation. The AP tests are pretty sorry in this respect as well.